"The goal is to introduce fans and creators to these upcoming release and drive interest through interactive activations, which can be shared on social media," said Doug Neil, Executive Vice President of Digital Marketing at Universal Pictures.

Neil added that the storyline of "Jem and the Holograms," which was updated from its origins as a 1980s toy line and TV cartoon series to showcase a girl whose singing talent gets discovered through online videos, fit with VidCon crowd.

"Her story resonates with attendees due to the similarities with the stories of many of the content creators who are present at VidCon," he said.

A host of other companies moved to capitalize on the crowd.

Canon brought its camera products and gave away tote bags and other gear to show aspiring filmmakers the latest technology in the field. Air Optix Colors let influential convention goers try on its color contact lenses. It then treated them to a makeover by celebrity makeup artist Scott Barnes, who is also a member of its Color Squad, which creates online makeup tutorials on behalf of the brand.

'Drive continued loyalty and foster growth'

Harriet Taylor | CNBC

Fans at VidCon in Anaheim, Calif.

NBC created a stage, which featured two TV shows and one digital series. "The Tonight Show with Jimmy Fallon" hosted a slapjack booth where players who lost at blackjack would get hit with an oversized hand-shaped pillow. The "slap" was recorded in slow motion.

It also brought the famous rotating chair from "The Voice," and created edited GIFs of people with fire shooting out of their hands in honor of new online show "Heroes Reborn." All pictures and clips were shareable on social media.

"We know how passionate and vocal these fans can be," said Rob Hayes, Executive Vice President of Digital for NBC Entertainment. "Giving those fans, especially the younger fans who are so active on YouTube and other digital platforms, a chance to interact with their favorite shows is a great way to drive continued loyalty."

Others, like Vimeo, which hosted several industry panels in its sponsored room, saw VidCon as an opportunity to remind online influencers about how it stacks up against competitors like Google's YouTube and Apple iTunes—and how users might be able to earn more.

It showcased several of successful Vimeo On Demand movies, including "Smosh: The Movie," "Bad Night" and "The Chosen." Vimeo pointed out that it offers a 90/10 revenue split with its content creators through the program. (For comparison, Apple divvies up profits 70/30.)

"Vimeo is here to engage online video creators, and to show them how, creator to creator, they can make money online," said Greg Clayman, General Manager of Vimeo's Audience Networks.

However, it's not all pure marketing: many brands came to VidCon to scout potential talent. NBC's Hayes pointed out that the network works with a lot of online creators already to help promote its shows.

"VidCon is a chance for us to continue to build those relationships and let the creators know we see ourselves as part of this community, and we want to foster its growth," he said.

Time Inc.'s People and Entertainment Weekly hosted a three-day Creator Track interview stage with some of the biggest online names. While the activation allowed the magazines to showcase their access to today's hottest celebrities, it also allowed them to see which influencers were resonating the most.

"I think we have to sort of break ourselves from the notion that it's about a writer and editor on editorial," said Will Lee, the editorial director of People.com and EW.com. "[Online creators] could bring in a different talent, a different voice and a completely different energy. They're not to meant fill roles, but we have a new paradigm now."

Note: NBC and Universal Pictures are part of NBCUniversal, which is the parent company of CNBC and CNBC.com.